Quantum entanglement is the key resource that makes quantum information-processing machines more powerful than classical ones. In this project in quantum-mechanical engineering with superconducting qubits – electronic circuits that are engineered “artificial atoms” – I will create quantum-entangled steady states that never decay, as long as the qubits are subject to external microwave drive fields. I will do this by designing the driving protocol and the qubits’ dissipative environment – “quantum bath engineering” – in a circuit-QED architecture with carefully designed qubit-resonator couplings and resonator loss rate. The dominating transition rate can then act to prepare the system, rapidly and with high fidelity, in the desired singlet as a steady state of the dissipative time evolution. This is a new concept: only very few related experiments have been done with other physical systems, and none with superconducting qubits. Compared to the standard way of preparing entangled states – by one- and two-qubit unitary gate operations – this scheme has several advantages, chiefly the resilience to energy relaxation of the qubits because the induced transitions and the relaxation processes bring the system back to the desired state. I already have preliminary and promising results in this project, and good international collaborations. The excellent infrastructure and great environment at Chalmers University will help me succeed, which in turn will ensure my integration into the European research community. This research field is internationally very competitive, in particular as superconducting qubits are emerging as the perhaps most viable type of system to base future quantum computers and quantum simulators on. It should therefore be a strategic interest for the EU to continue being on the forefront in quantum technologies.
Forskare vid Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
Funding years 2014–2018
Areas of Advance